Holy social networks, Batman! An estimate from Ancestry.com founder Paul Allen suggests Google+ may hit the 10 million member mark in the next 24 hours. If the invite button is left on, this number could climb to 20 million by the weekend.

Allen (not be confused with the Microsoft co-founder) uses a surname-based model to calculate these subscriber numbers. He's been using this model since he first joined and claims it is quite accurate. Judging by the amount of spam I already see in my stream, I would have to agree. [Paul Allen]